Various crank/connecting rod designs are generally well known. Such designs are primarily used in human powered bicycles or non-human powered vehicles with internal or external combustion engines, be it fossil fueled, steam or other propellant, used on land, sea or air. The purpose of such a design is to transmit the force from the power source to the driving mechanism.
Mechanisms have been proposed for more efficient bicycles by displacing the top dead center. Examples of such mechanisms are disclosed in U.S. Pat. No. 4,793,208 [displaces top dead center] to Bregnard et. al. U.S. Pat. No. 4,807,491 to Stuckenbrok, U.S. Pat. No. 4,882,945 to Trevizo (1989), and U.S. Pat. No. 4,960,013 to Sander (1990) disclose systems for mechanically extending and shortening the crank. U.S. Pat. No. 4,816,009 to Philipp (1989) further refined these techniques.
Similar and more recent techniques for increasing the efficiency of the bicycle in particular have been used: U.S. Pat. No. 5,207,119 to Garneau describes a system that varied the length of the pedal arm, the system of U.S. Pat. No. 5,199,324 to Sain rotated the crank arm, U.S. Pat. No. 5,179,873 to Girvin (1993) teaches the use of a hollow crank to reduce crank weight without loss of strength, the crank of U.S. Pat. No. 5,157,988 to Pinkstock (1992) used a spring to store energy, U.S. Pat. No. 5,060,536 to Boys (1991) described the use of a flexible crank arm with a rectangular cross section, U.S. Pat. No. 5,010,785 to Romero (1991) provided for a tubular crank arm, and U.S. Pat. No. 5,125,288 to Amiet (1992) taught the use of an arcuate crank that could be filled with mercury.
In the realm of internal or external combustion engine connecting rods, U.S. Pat. No. 4,890,588 to Tillman described a system that rotated the crank arm/connecting rod a number of degrees past top dead center. U.S. Pat. No. 4,957,069 to Mederer suggested a prolonged connecting rod, U.S. Pat. No. 4,966,109 to Pusic, et al. taught the use of a hydraulic connecting rod for both internal-combustion and steam engines, and U.S. Pat. No. 5,136,987 to Schechter, et al. provided for a hydraulically variable connecting rod to vary length which was improved in U.S. Pat. No. 5,178,103 to Simko. U.S. Pat. No. 5,201,287 to Blish described a system that used an extension rod operated hydraulically, mechanically or electrically to vary stroke length. U.S. Pat. No. 4,974,554 to Emery (1990) taught to raise the piston head at top dead center to increase the mechanical and input/output efficiencies of an engine (internal or external combustion) by providing for an increased effective moment arm offered by the crankshaft rod journal during the period of peak combustion pressure. U.S. Pat. No. 5,025,757 to Larsen provided for pivoting the engine block to change the top dead center distance. U.S. Pat. No. 5,186,127 to Cuatico (1993) used an off-set connecting rod to obtain a better mechanical advantage in the internal combustion engine.